There are a lot of analytical methods used for detection of pesticide residues in food. All of them include sample preparation, extraction, purification, separation and detection of a particular compound. Once the pesticide is extracted from the sample it must be separated from other extracted compounds with gas (GC) or liquid chromatography (LC), rarely with thin layer cromatography (TLC). For all cromatographic metods in common is the existance of fixed (stationary) and mobile phase. Gaseous or liquid mobile phase carries the sample components through the stationary phase, so separation is based on differences in speed of movement of components through the stationary phase. The final step of the analysis (detection) allows the formation of an electric signal that is proportional to the intensity of some features of mobile phase or a substance that is eluted and can be used to measure the amount of pesticides that pass through the column. All the techniques used will
continue to improve with tendation to increase the number of pesticides that can be determined with one method in one sample.